The variance depends on the spread of the cluster means and not at all on the spread within a cluster. The design effect against simple random sampling of the same number of elements is returned.
Value
List with estimate, se, ci_lower,
ci_upper, cluster_mean, between_var,
within_var, deff, rho, m, k.
Details
Formula: ybar_c = (1/m) sum_i ybar_i; v(ybar_c) = (1 - m/M) s_b^2 / m, s_b^2 = sum (ybar_i - ybar_c)^2 / (m - 1)
References
Cochran (1977), Sampling Techniques, 3rd edition, Chapter 9. Chapter 9 was NOT in the scanned excerpt available to this batch, so the standard published form is used; the finite-population factor (M - m)/M matches the convention of the sibling Cochran modules.
Examples
V <- c(1, 2, 3, 4, 5, 6, 7, 8)
Clus1(V)
#> $estimate
#> [1] 4.5
#>
#> $se
#> [1] 0.8660254
#>
#> $ci_lower
#> [1] 2.802621
#>
#> $ci_upper
#> [1] 6.197379
#>
#> $cluster_mean
#> [1] 1 2 3 4 5 6 7 8
#>
#> $between_var
#> [1] 6
#>
#> $within_var
#> [1] 0
#>
#> $deff
#> [1] 1
#>
#> $rho
#> [1] NaN
#>
#> $m
#> [1] 8
#>
#> $k
#> [1] 1
#>
#> $method
#> [1] "One-stage cluster sampling, equal cluster sizes"
#>
#> attr(,"class")
#> [1] "morie_rich_result" "list"
